Distributor rotor lock



J. L. ARTHUR ETAL DISTRIBUTOR ROTOR LOCK June 15, 1943.

Filed Aug. 2o, 1941 e WM .M/n fw ozmew E. Ta .MN N .0 R E O. v T mslm M fm mw mm/ @t5/Egel? l Patented June 15, 1943 DISTRIBUTOR ROTOR LOCK .l ames L. Arthur and William Da'Schrope, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delafare Application August 20, 1941, Serial No. 407,645

(Cl. 20G-19) 7 Claims.

This invention relates to improvements in ignition apparatus for internal combustion engines and more particularly to the means which control the timing and the distributing of spark impulses to the cylinders of the engine.

One of the objects of the present invention is to improve the construction and operation of such apparatus, to provide yieldable locking means which will lock the distributing rotor with a circuit breaker cam whereby the assembly of said elements may be readily secured together and easily disassembled and which may be assembled so as to be handled as a unitary structure and thereby eliminate the necessity of individual handling of each element.

Another object of the present invention is to provide a simple form of locking means which will maintain a predetermined operating relation between the distributing rotor block and the distributing posts of a distributor cap irrespective of the speed of revolution of the distributing rotor block; irrespective to the position ofthe parts relative to the vertical and irrespective to the vibrations towhich the parts are subjected while in operation.

Another object of the present invention resides in the provision of a novel manner of holding the distributor rotor block assembled With the circuit breaker cam, in which the distributor rotor is held againstaccidental removal and maintained in a predetermined relation with respect to the cam through the agency of a length of spring wire doubled back itself and deformed in a loop and adapted to embrace a portion of the rotor which has a hole for receiving the portion of the wire which is doubled back on itself to form a prong which extends through the lhole and has frictional engagement with the cam.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. l is a fragmentary longitudinal sectional View of an ignition timer distributor unit having a rotor locking device embodying the present invention.

Fig. 2 is an enlarged sectional view taken on the line 2-2 of Fig. 3.

Fig. 3 is an enlarged sectional view taken on line 3-3 of Fig. 2.

Referring to Figs. 1 to 3, an ignition timer cup 20 "supports the-distributorV cap-2 l housing a distributorrrotor "block'r22; having a-socket -lined with a cup-shaped member 23 the cross sectional contour is generally circular but includes a fiat 24 as shown in Fig. 2. The member 23 provides a driving connection with a similarly shaped reduced hub 25 of an ignition timer cam 26 which drives the rotor block 22. The free end of the hub 25 is provided with a bevel 2l. The block 22 carries a segment 28 which sweeps past a circular row of distributor inserts or posts 29 with which the spark plug cables (not shown) are attached, The rotor block 22 carries a leaf spring 30 electrically connected with segment 28. The leaf spring carries a button 3l which cooperates With a contact 32 carried by the lower end of an insert 33 with which the high tension lead from the ignition coil (not shown) is connected.

It Will be understood that sparking between the segment 28 and ends of the posts 29 causes the formation of an oxide of nitrogen from the air which, upon immediately mixing With moisture in the air, produces nitric acid which if allowed to accumulate would have a very corrosive effect on the metal parts of the distributor. It is therefore necessary to provide proper ventilation. Therefore, the cap 2l is provided with side openings 34 for the inlet of fresh air and the outlet of air carrying nitric acid fumes. In order to cause fresh air to pass within the confines of the distributor cap 2l and nitric acid fumes diluted with air to pass out, the air within the distributor cap is agitated violently by an up-and-down motion produced by particularly constructed vanes 35 which are part of a continuous flange 36 with which the rotor block 22 is` provided.

The rotor thus far described is shown in assembled position in Fig. 1 and the construction is similar to that described in the ccpending application of James L. Arthur, Serial Number 274,190, filed May 17, 1939. The rotor block in that instance is not locked to the cam,

The particular construction of the rotor block 22 makes it advisable that the rotor block 22 should be stabilized so as not to cause the segment 28 to engage or strike the inserts or posts 29 which project a substantial distance below the top Wall of the cap 2l. It is important that timer cam 26 and the rotor assembly 22 operate in a predetermined relation, and that relation be maintained.

In order to secure and yieldingly maintain the proper relation of the rotor block with respect to the distributor cap, there is provided in the present invention a particularly constructed ing the-.rotor block4 in` proper .operative position relative to lthe posts and also the circuit breaker cam. Ihe rotor block 22 has a boss 4| molded about the cup-shaped member 23 having flat 24. In the present instance, the boss 4l is preferably formed with a permetrical groove 42 having a through opening 43 in communication with the groove 42 and the interior of the cup-shaped member 23. It will be noted that insulating material about the opening extends into an opening 44 provided by the cup-shaped member 23 in iiat 24. This insulating material about the opening assists in holding the cup-member in assembled relation with the rotor. ing 44 is in substantial alignment with a'tapered detent or recess 45 provided in a corresponding flat on the hub 25 of the circuit breaker cam 23.

The spring rotor lock 40 in the present instance, comprises a length of spring wire of suiicient tensile strength which is doubled back on itself to provide a U-shaped member. The U- shaped member is deformed into a loop to provide an arcuate portion 46 with the extremities 410i the arms of the U ared outwardly as clearly shown in Fig. 2. The portion of the length of wire doubled'back on itself, is bent straight and substantially diametrically of the arcuate portion to form a hook or prong 48. The length of the prong, which is the distance between the end of the yoke and the portion which joins the arcuate portion, is greater than the A length of the opening 44 so that the prong can move radially within the opening to permit assembly and disassembly of the rotor with the circuit breaker cam. It is to be understood that the lock spring may be made from spring bar stock,

but it is preferred that the lock spring be made from a length of spring wire bent back upon vitself so as to provide a prong that is free of burrs. Thus, when the rotor is assembled or removed from the cam the surface of the hub will not be scratched.

By referring to Figs. 2 and 3 it will be noted that the resilient rotor lock 40 assembled with hub 4I or the rotor block 22, the prong 4B projects a substantial distance through the opening 43 with the smooth cam portion 49 engaging one side of the tapered recess 45 and the arcuate portion 46, shown in full lines, will Contact space points in the bottom of groove 42. The dot-anddash linesin Fig. 2 illustrate the conguration of the resilient lock in its normal position. It will be noted that the diameter of the arcuate portion 4t is less than the diameter of the groove 42. Thus when the resilient lock 40 is assembled in the groove 42 on the hub, the arcuate portion will contact diiferent points of the bottom wall of the grooveand urge the prong 48 through the opening 43 so that the end 48 will extend beyond the internal marginal walls of the socket of member 22 and toward the common axis of the rotor and consequently, when the rotor is to Abe assembled upon the hub 25 the rotor will have to be forced thereon due to the fat the prong 43 extends a short distance within the socket of member 23 as indicated by dash lines 49a, Fig. 3. It is obvious as the rotor 22 is beingforce-d on the hub 26, the lower side of the rounded end 49 will engage the bevel 21 forcing the prong 48 outwardly so as to permit easy assembly of the rotor to the hub. After the rotor hasfbeen moved downward a predetermined distance the prong 48 will be forced into frictional engagement with the upper portion of the tapered recess or detent 45, as viewed in Fig. 3, due to the force exerted by the arcuate portion upon the The openrotor.

prong 49. This force is suiiicient to urge the rotor downwardly until the rotor rests on the top of the hub or the bottom of the boss sits securely upon a shoulder formed by the hub 26. The camming action between the prong 48 and recess 45 prevents accidental removal of the rotor from the cam. Thus, manual pull or other pull forces are necessary to remove the rotor from the cam.

When it is desired to remove the rotor block from the cam, a pulling force is exerted upon the As the pulling force is exerted, the prong is forced radially outwardly by the taper of the ldetent and out of locking position so as to permit readily the removal of the rotor block from the circuit-breaker cam.

From the foregoing description it will be seen that the lock member tends to force positively the rotor block downward against the shoulder, since the cam portion 49 which engages .the taper of the detent is constantly urged inwardly while the taper tends to move the cam portion 49 downwardly as viewed in Fig. 3 and maintains the locking relation. In this manner, the rotor is held solidly on the circuit breaker cam and prevents the outer extremity of the segment 28 from striking the lower ends of the distributor cap inserts or posts 29. Further the spring locking element tends to stabilize the rotor block during its operation in the distributor and prevents the possibility of the block from rising, due to engine vibrations.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. v

What is claimed is as follows.

1. A coupling device comprising a removable member having a recess adapted to be mounted on a shaft; a body carried by the removable member,V said body having a boss provided with a permetrical groove and a radial opening in communication with the groove and in sub stantial alignment with the recess; a prong extending through the opening; and resilient means associated with the prong embracing the groove, said resilient means urging the prong radially inward into the recess thereby yieldingly hold-v ing the body against accidental axial movement in respect to the shaft.

2'. A coupling device comprising, a shaft hav` ing a non-rounded projection provided with ya side `tapered recess, a body having a boss provided. with a non-rounded socket for receiving the projection, said boss having an annular groove on its periphery and having an opening connecting the groove with the socket and in substantial alignment with the recess when assembled with the shaft; a length of spring Wire doubled back on itself and formed into a loop adapted to embrace the groove of the'boss with that portion of the wire, which is'doubled back, extending through the opening and intothe tapered recess of the shaft, said doubled back portion being forced inwardly by the resilience of spring embracing the groove whereby the body is cammed downwardly on non-rounded portion of the shaft and maintained yieldably in assem bled relation with the shaft. I

3. A coupling device comprisinga driven shaft having a non-rounded projection4 with afdete'nt therein; a body member having a boss provided with "a non-rounded socket adapted to receive the projection, said boss having a circ'umferen` tial groove and having an opening communicating with the groove and in substantial alignment with the detent; and stiff resilient means including an arcuate portion for embracing the groove and having a straight portion extending through the opening and into the detent whereby the body member will be maintained in position, said body member being capable of being removed from the shaft by force exerted upon the body member.

4. In a retaining device the combination with a drive member having a reduced non-rounded projection to provide a shoulder, said reduced portion having a tapered detent between its free end and the shoulder; a body member having a boss provided with a non-rounded socket to receive the projection, said boss having a groove on its periphery and having a through opening in communication with the groove and in substantial alignment with the detent; and means for locking the body member with the drive member, said means comprising a length of spring wire bent back upon itself and formed into a loop with the free ends thereof embracing the groove and the portion of the wire bent back 1 upon itself extending through the opening and engaging the detent to urge the boss toward the shoulder and prevent accidental removal of the body member from the drive member.

5. The combination With a driven member provided With a non-rounded extension having a recess, of a body member having a boss provided with a socket complementary to the contour of the extension for receiving the extension, said boss having a permetrical groove and having a l' through opening in communication with the groove and in substantial alignment with the recess of the extension; and yieldable locking means for preventing accidental removal of the body when in assembled relation with the driven member, said means comprising a length of spring wire having an arcuate portion of smaller dimension than the bottom wall of the groove for embracing the groove and having a straight portion bent diametrically of said arcuate portion and projecting through the opening of the boss and extending into the recess of the extension to retain the body member thereon.

6. A yieldable locking means for two intertting members comprising, a length of stiff spring wire formed into a U-shaped member, one portion of the member, which includes the extremities of the spaced arms, being deforme-d to prou vide an arcuate section adapted to embrace an outer member of greater dimensions in gripping relation and having the portion, which is the yoke portion of the member, extending in a straight shank and toward the axis of the arcuate section, said shank adapted to project through an aperture of the outer member and into a recess in the inner member whereby the outer member is yieldably locked to the inner member.

7. In a coupler the combination comprising, a shaft having a side recess; a sleeve adapted to fit over the shaft in non-rotatable relation therewith and having an opening; a prong in said opening; a stiff spring wire carried by the sleeve for projecting the prong into a position so that it Will extend into the recess of the shaft whereby the shaft and the sleeve may be yieldingly held in assembled relation, said spring wire being attached to the prong to provide a single unit for assembly and disassembly with and from the sleeve and said spring also being formed for embracing the sleeve in gripping relation to prevent its accidental removal therefrom.

JAMES L. ARTHUR. WILLIAM D. SCHROPE. 

